Strapping material is used in a wide variety of applications to secure or bundle loads. The strap material is typically metal or plastic and can be applied to the load using either a manual sealer or a powered sealer. Powered sealers can be pneumatic or electric and can be hand-held or machine-frame type machines. Non-powered (manual) sealers are typically hand-held or hand-operated tools.
The seals (for both metal and plastic strap) can be of the seal-less type or of the crimp seal type. In a seal-less seal or joint, the material is welded to itself (if plastic) or mechanically joined as by locking cuts and projections. Crimp seals, on the other hand, use a band that is bent or wrapped around overlapping portions of strap and mechanically crimped onto the strap. In such a joint, the seal is compressed onto the strap material and the strap material is deformed so as to be secured in the seal.
There are two principal types of seals that are configured based upon the size or width of the strap on which the seal is positioned. For both ½ and ⅝ inch strap, the seals are formed with a base portion and upstanding legs. A top portion of the seal extends from one of the legs, inwardly, forming an asymmetrical design. The legs are commonly referred to as a long leg (the leg that has the top portion of the seal extending therefrom) and a short leg (that leg that is only the upstanding side portion). For ¾ inch strap, the seal is symmetrical. That is, the top portion of the seal is formed from inwardly extending portions of both legs.
In many such seals, the seal is cut, at least in part and is urged into the material to create an interference type of fit. In this manner, portions of the strap and portions of the seal are forced from their respective bodies, into the other material. That is, the strap and seal are cut and bent into each other so that the materials are not only held by compression, but also by interference of the crimp seal with the strap “pulling” from the seal.
Known tools that are used to crimp the seal onto the strap are leverage-type (or lever-action) tools that include a pair of handles that are linked to jaws that pivot inwardly to compress the seal. The seal is held between the jaws and rests on an anvil surface of a shear. In such known tools, a set of jaws and shears are stacked to increase the area over which compression of the seal occurs and the number of locations at which the seal is crimped.
Current jaws may not fully capture the long leg of the seal resulting in an incorrect seal formation. With an incorrect seal formed, the user would then need to install a completely new seal to the strap. This additional installation results in an increase in the amount of time needed to band a load as well as added expense. There is also the possibility that the incorrect seal formation would go unnoticed which could result in the joint in the banding failing at a later point in time.
In tools where the jaws may overlap they tend to have jaws that are longer, but are not in-line with each other. The notchers are bent to allow the jaws to overlap. In this configuration the jaw also overlaps the anvil surface of the notcher. This design has several drawbacks. One drawback is that this overlap significantly increases the force a user must apply to operate the tool properly and crimp the seal. A second drawback that is attributable to the bent notcher design, is that this now requires two different shorter jaws to fill in space in the tool.
Other tools are not symmetrical and instead have a different set of jaws on each side of the tool, one long set and one shorter set. This configuration requires the user to pay close attention to the position of the seal with respect to the tool before crimping to make certain that they are both facing in the proper direction with respect to each other and with respect to the seal.
Accordingly, there is a need for a front action seal tool with symmetrical overlapping in-line jaws for use with strap material. Desirably such a tool is used to easily and quickly form a high reliability seal on overlapping strap material with less force and more reliability than tools already in use. Such a tool can be used with seals of different sizes, without having to change the jaw elements and can be used with a seal at any position within the tool.